Wednesday June 25, 2025
PhysOrg —
A trade-off between tooth size and jaw mobility has restricted fish evolution, Nick Peoples at the University of California Davis, US, and colleagues report in the open-access journal PLOS Biology .
Ray-finned fish are a diverse and widespread group, representing 99% of living fish species. Two key adaptations have helped them thrive: large teeth and extendable jaws.
Fish with larger teeth can access a wider range of food sources, while the ability to rapidly extend the upper jaw allows fish to hunt fast-swimming prey by using suction forces to pull them closer. However, these two innovations are rarely found in the same fish species. To find out why, researchers captured high-speed videos of the feeding behavior of 161 species of ray-finned fish.
They analyzed how different strategies for capturing prey had evolved alongside tooth size across the evolutionary tree. They found that small-toothed fishes used a wider variety of methods to capture prey, including extending their jaw to create suction.